Vulnerability · Published Jul 30, 2026 · Assigned by icscert
CVE-2026-66349MZ Automation libiec61850 Out-of-bounds Read
Medium 6.5
In plain English
A medium-severity out-of-bounds read in libiec61850 from MZ Automation GmbH. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 22% of all known vulnerabilities).
Official description
The MMS server connection handler contains a flaw in its processing of BER-encoded request data. When an MMS confirmed request PDU containing an extended BER tag is received over an established session, the decoder may advance its internal buffer incorrectly due to a missing bounds check. This results in a one byte heap out-of-bounds read and causes the MMS service process to terminate, leading to a denial-of-service condition.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| MZ Automation GmbH | libiec61850 | 0 – before 1.6.2 |
Weakness: CWE-125 · Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H